| 摘要 |
PURPOSE:To prevent compression of wet steam, by switching the capacity of a compressor when the state point determined by the detected suction pressure and temperature gets out of a tolerable region, and controlling the degree of superheat to a proper value to meet with variation of the atmospheric temperature. CONSTITUTION:Under the state that the temperature in the cabin of a vehicle is high, a compressor is operated at a rate of 100%, and the cooling capacity and the cooling load imposed on the compressor are substantially equal to each other, switching of the compressor capacity is not caused since the actual state point A of operation determined by the suction pressure and temperature is located within a tolerable region E preset in a memory by a controlling means to have a certain degree of superheat. Subsequently, when the cooling capacity becomes greater than the actual cooling load with lowering of the temperature in the cabin and resultant drop of the cooling load, the degree of superheat is lowered and the point A gets out of a line H1 of the degree of superheat in the region E, whereupon the capacity of compressor is decreased by a signal given from the control means, so that the point A is brought back to a point within the region E. On the other hand, in case that the point A gets out of a line A2 by reason of the fact that the cooling capacity is lower than the cooling load, the capacity of the compressor is increased. |
